1. Field of Invention
This invention relates generally to oral hygiene compositions which are brushed or otherwise applied to surfaces of the teeth and adjacent gum tissues, and in particular to a composition which includes an alkaline metal compound powder, the composition not only acting to clean and whiten the teeth but also to counteract the formation of plaque, to neutralize acids responsible for tooth decay, and to remove extraneous material from the surfaces of the teeth which otherwise discolor the teeth.
2. Status of Prior Art
As noted in the Leopold U.S. Pat. No. 4,485,089, the typical toothpaste for cleaning and whitening teeth makes use for this purpose of a dental abrasive, such as silica. Such abrasives score and damage the enamel surface of the teeth. Also included in a typical toothpaste is a cleaning agent such as dicalcium phosphate, water and a humectant, such as glycerin or sorbitol. A humectant serves to retain moisture in the toothpaste, particularly, at the nozzle of the tube where the paste can be in prolonged contact with the air.
A conventional toothpaste mainly carries out a cosmetic function. While it serves in conjunction with a toothbrush to clean the teeth and improve their appearance, the toothpaste does little to prevent tooth decay, to inhibit the growth of plaque or to in other respects maintain the teeth and gums in a healthy condition.
As noted in the Libin U.S. Pat. No. 5,000,949, dental plaque is constituted by a thin layer of mucuaginous film which is subject to invasion by colonizing bacteria. Metabolic activity of these bacteria in the presence of dietary carbohydrates leads to the production of acetic and other acids. These acids attack soft gum tissue, thereby causing gingivitis; that is, the redening and swelling of the normally pink gums, often accompanied by bleeding. These acids also react with the calcium of the teeth and the resultant decalcification of the organic matrix or dentin is such as to allow for the further invasion of bacteria and liquefying enzymes. Hence vital to sound oral hygiene is the reduction and control of dental plaque.
The Libin '949 patent provides an oral hygiene composition that includes a blend of magnesium peroxide and calcium peroxide compounds which together release active oxygen functioning as an oxidizing germicidal agent to destroy anerobic bacteria associated with dental plaque and periodontal diseases.
Toothpaste compositions of the type heretofore known make use of relatively coarse abrasive agents, such as silica. While these serve to whiten teeth, with repeated use, they wear away the superficial surface of the tooth enamel. Because this enamel does not regenerate, the teeth become subject to attack and decay. Moreover, most toothpastes are somewhat acidic in nature, and the combination of acidity and abrasiveness will in time destroy porcelain and other bonding agents which simulate natural enamel and are now commonly applied to teeth surfaces to afford a more attractive veneer.
It is desirable, therefore, that a toothpaste in cleaning and whitening teeth, not do so at the expense of the natural enamel or the bonding agent which simulates the natural enamel.
And it is also desirable that the toothpaste promote the health of the dental regions in the oral cavity.